-------VC System, Retrofitting R-12 to R-134a-oroup: 87

Number: 95-03

Date: September 15, 1995

Subject:Ale System, Retrofitting R-12 to R-134a

Model(s):All 1986 - 1993

Please read all sections of this Bulletin thoroughly before proceeding with retrofit!

At customers request and expense, Audi models from 1986 to 1993 equipped with either a "Nippondenso" or "Zexel", compressor may beretrofitted to use refrigerant R-134a.

Different R-134a retrofit parts and procedures are necessary for each compressor type. Refer to the Table of Contents for applicableinstructions.

Notes:1\ Retrofitting to refrigerant R-134a is not reimbursable under warranty.1\ Retrofit is not planned for vehicles equipped with "York" or "Delco-Air" compressors.1\ Always confirm compressor type prior to retrofitting.1\ Always check Ale system integrity and function before proceeding with retrofit.

Caution:Part numbers are for reference only. Always check with your Parts Dept. for the latest parts information.

CautionsCaution

Always use separate refrigerant recovery, recycling and recharging service equipment for R-12 and R·134a systems. If the same piece ofequipment is used for both R·12 and R-134a systems, residual traces of refrigerant will contaminate and damage the equipment. Serviceequipment includes recovery, recycling, recharging station, vacuum pump, manifold gauges, etc.

CautionDo Not blow compressed air and nitrogen through the compressor. Refrigerant circuits retrofitted to use R-134a must not be rinsed withagent R-ll.

Replacement compressors are filled with nitrogen. When updating replacement compressors prior to system retrofit, relieve nitrogencharge by carefully loosening protective caps on suction and discharge ports. If gas does not escape when removing protective caps,assume leakage and do not install compressor.

Always replace accumulator if refrigerant circuit is left open.

Due to residual amounts of mineral based refrigerant oil in systems retrofitted to use refrigerant R·134a, the newly installed PAGrefrigerant oil will discolor immediately after use. This is normal and does not indicate a refrigerant related fault.

Compressor IdentificationNippondenso compressor:

Look for suction and discharge fittings that attach to compressor manifold at side of compressor housing

Also look for Nippondenso identification label at end of compressor

Zexel compressor:

(•..,Look for suction and discharge fittings that attach to compressor manifold at end of compressor housing.

Also look for Zexel compressors equipped with angled suction/discharge fittings mounted to the end ofthe compressor (for clearance)

System PreparationI

r. Review all Cautions, Warnings and AlC refrigerant system safety measures stated in appropriate model repair information,

/\ Always use Underwriter's Laboratory (UL) approved refrigerant service equipment such as Kent Moore ACR3, ACR4 or equivalent.

, Before proceeding with retrofit, perform a visual inspection and functional test of complete AlC system; including instrument panel outlet.temperature, air distribution, refrigerant system components, system pressure and leak test. Repair/replace parts as necessary.

/\ Before proceeding with retrofit, ensure all replacement parts, necessary special tools and equipment are available.

/\ Always refer to the most recent parts information for affected models when replacing damaged or leaking R-12 refrigerant system parts(including the routine replacement of O-rings).

/\ If replacement of damaged or leaking refrigerant components is necessary, blow compressed air followed by nitrogen through theremaining (except compressor), disconnected, free tlowing system components before re-assembly in order to remove moisture, impuritiesand remaining refrigerant oil.

/\ Any refrigerant system component replaced prior to retrofitting the system to R-134a requires PAG refrigerant oil to be added to thecircuit.

/\ All replacement compressors must be updated prior to installation and subsequent R-134a retrofit:/\ Nippondenso compressors, See Nippondenso Compressor AlC System in this bulletin.

/\ Zexel compressors, See Zexel Compressor Ale System in this bulletin.

Replacement Compressor UpdatingReplacement Nippondenso compressor, updating

Note:Replacement compressors are factory filled with R-12 compatible compressor Oil which must be drained and replaced with appropriatequantity of PAG refrigerant oil.

Only when replacement of a damaged or leaking Nippondenso compressor is necessary prior to system retrofit, update the replacementunit as follows:

Obtain Nippondenso retrofit kit:Part No. 4AO 298 107 A

Relieve nitrogen charge in replacement compressor by carefully loosening protective caps on suction and discharge ports.Drain and measure amount of existing refrigerant oil at high and low service ports (rotating compressor via the clutch will aid draining).Replace shaft seals (if necessary"), See Retrofit Procedures.Replace manifold seals (if necessary*), See Retrofit Procedures.Fill with same amount ofPAG refrigerant oil measured when draining.

*Notes:1\ Replacement compressors from the following manufacturer code have R-134a compatible shaft and manifold seals which do not need

replacement:

1605 and higher.2893 "3901

/\ On these units, only change refrigerant oil to FAG type.

Required PartsParts required, NC system with Nippondensocompressor

All models require the following parts:

~. /\ Nippondenso retrofit kit:Part No. 4AO 298 \07 A

Consisting of:

2 containers (250cc) PAG refrigerant oil for Nippondenso compressors: Part No. G 052360 A2.Manifold O-rings and manifold prechamber moulded gasket.

- 'Compressor shaft seal.R-134a identification labels and tag.

1\ Service valve adapter/label kit:Part No. 357 820 794

/\ Restrictor*

/\ Restrictor O-rings*

/\ Compressor O-rings*

/\ Accumulator O-rings*

1\ Accumulator (see chart)

MOdetlproduction Accumulator Part No.90/90 quattro 443 271 161 A

Coupe quattro BAD 820191 8

5000/5000quattro 4AO 820191 E100/1 00 quattro200/200 quattro

VB quattro 441 820191 A

Accumulator applications, System with Nippondenso compressor

CautionPart numbers are for reference onlyAlways check with your Parts Dept. for the latest parts information.

Retrofit ProceduresRetrofit procedure, AlC System with Nippondensocompressor

Discharge and capture refrigerant R-12 using Kent Moore ACR3 or equivalent.Evacuate system to remove any contaminants.Remove compressor.Drain and measure amount of existing refrigerant oil from high and low service ports (rotating compressor via the clutch will aiddraining).Replace shaft seals (ifnecessary*).Replace manifold seals (ifnecessary*).

* Compressors beginning with the following manufacturer code have shaft and manifold seals which are R-134a compatible. Thesecompressors do not need updating:

1605 and higher28933901

Refer to manufacturer code location -A-.On these units, only change refrigerant oil to PAG type.

If seal replacement is not necessary, proceed as follows:

Fill with same amount ofPAG refrigerant oil measured when draining.

Note:A If amount of oil drained from compressor exceeds 80 cc (2.7 fl oz), fill compressor with 80 cc (2.7 ft oz) PAG oil and fill the

remaining quantity via the replacement accumulator.

Reinstall compressor.Install new a-rings on compressor suction and discharge hose fittings.Remove accumulator.Clean outside of accumulator if dirty.Weigh the removed accumulator.Fill new accumulator with PAG refrigerant oil until the weight of the original accumulator is achieved.Install accumulator (use new a-rings).Replace restrictor. (use new a-rings).Identify and install correct R-134a adapters (from Kit Part No. 357 820 794) to service valve (5).

Low pressure service valve -1- (Blue), 7116" connectionHigh pressure service valve -2- (Red), 3/8" connection or 7/16"connection

Evacuate system for a minimum of 45 minutes using Kent Moore ACR4 or equivalent.Charge system with refrigerant R-134a.Turn compressor by hand via magnetic clutch approximately. 10 rotations.Perform quality check and leak testInstall new R-134a warning label, Part No. 8AO0 I0 132, in place of existing R-12 warning label on front crossmember or radiator cover.

Note:A R-134a warning label Part No. SAO010 132 lists three R-134a fill capacities. Cross out fill amounts not applicable to retrofitted

vehicle using a waterproof marker.

Apply new R-134a warning label, Part No. SAO010 132 E, to visible location on compressor housing.Affix new R-134a warning label, Part No. 8AO010 132 G, to first page of the vehicle Maintenance Booklet.

Nippondenso compressor shaft seals, replacing

Note:A Prepare a clean work area to ensure against seal leakage after installation.

M---.;a.s

Notes:1\ Nippondenso compressors have two different types of suction/discharge manifold assemblies;1\ manifold without pre-chamberA manifold with pre-chamberA Diagram shows manifold without pre-chamber.

Remove 4 bolts -A- Tightening torque 20 Nm (15 ft Ib).Clean surfaces -B-, remove all traces of refrigerant oil.Replace O-rings -C-.

Note:1\ Lubricate lightly with PAG refrigerant oil before installing.

Note:1\ Diagram shows manifold with pre-chamber:

Remove bolts -G-Tightening torque 20 Nm (15 ft Ib).

Remove manifold -B- from pre-chamber -A-.

Clean surface -C-, remove all traces of refrigerant oil.Replace formed seal -D- and O-rings -E-.

Note:1\ Alignment pin -F-, check for correct fit.

Replacement Compressor UpdatingReplacement Zexel compressor, updating

A

SiI..RI"-i"-C

Note:1\ Two types of replacement Zexel compressors are available; R-12 and R-134a type (labeled/identified as such). The R-134a type will be

the only replacement compressor available when supplies ofR-12 type run out.

~ ..Only when replacement of a damaged or leaking Zexel compressor is necessary prior to system retrofit, update the replacement unit as~~: I

Obtain Zexel retrofit kit:

C V.A.G1108B I-I

Fig. I Flange Seal (with collector ring-counter support),removing and installing

Remove clutch assembly,Repair Manual, Air Conditioning, Repair Group 87.

Insert puller -A- in groove -0- of flange seal.

Tighten sleeve by pushing in the tension ring -B-.

Remove shaft seal by turning screw -C-.

Note:/\ Lubricate lightly with PAG refrigerant oil before installing.

Fig. 2 Shaft seal (with collector ring)removing and installing

Insert puller -A- in shaft seal -B-, remove shaft seal.Check shaft for dirt and clean if necessary.

Check shaft of compressor and groove -C-, if sharp edges or burrs are present, remove and clean shaft.

Note:1\ Lubricate lightly with PAG refrigerant oil before installing.

Install clutch assembly and adjust gap.

Nippondenso compressor manifold seals, replacing

Note:Coat lightly with PAG refrigerant oil before installing.

1 - Hex nllt M8• lightening torque:

20 Nm (15 ft Ib)2 - Spring washer

3 - Clutch disc

4 - Spacers to adjust gap dimension5 - Atted spring6 - Felt ring

7-Lockring

• Install lock ring with smooth side to compressor• Compress spring on shaft seal to ensure lock

ring f1tiS in groove

8 - O-ring seal

• Replace• Installed In flange seal

9 - Flange se&1(with collector rlng-counterSUppCI1)

• R8place• Removing and Installing. = Fig. 1

10 - Shaft seal (with collector ring)+ Replace• Remo"ing and instaJling ==> Fig. 2

Part No. 4AO 298 107

Relieve nitrogen charge in replacement compressor by carefully loosening protective caps-on suction and discharge ports.

- .ln both cases (R-12 or P-134a type), replace pressure relief valve.

Note:R-12 type replacement compressors are factory filled with R-12 compatible compressor oil which must be drained,

Drain and measure amount of existing refrigerant oil via oil drain plug (rotating compressor via the clutch will speed draining).

Fill with same amount of FAG refrigerant oil.

If amount of oil drained exceeds 80 cc (2.7 fl oz), fill compressor with 80 cc (2.7 fl oz) FAG oil and the remaining quantity via thereplacement accumulator.

Proceed with system retrofit.

Notes:/\ R- I34a type replacement compressors are factory filled with R-134a compatible compressor oil. This oil does not require changing.

/\ R134a type replacement compressors require the suction/discharge manifold from the original (R-12) compressor to be removed andinstalled on the replacement unit.

R134a Zexel replacement compressor, modification

/\ (applies only when replacing damaged or leaking R-12 Zexel compressor with R-134a Zexel compressor)

Notes:/\ Prior to system retrofit, R-134a type replacement compressors require interchanging the manifold plates from the existing compressor

to the new compressor:

1\ If equipped, angled suction/discharge manifold adaptors must be interchanged

Prepare a clean work area to ensure against seal leakage after installation.

Relieve nitrogen charge in replacement compressor by carefully loosening protective caps on suction and discharge ports.

Remove pressure relief valve from manifold plate -B- of existing R-12 compressor and replacement R-134a compressor.

B A

1--1

Remove bolts -A- from both the existing compressor and new compressor.Tightening torque 20 Nm (15 ft Ibs).Remove manifold plate -8- from both compressors.Clean surface -C- on R-134a replacement compressor; remove all traces of refrigerant oil.

Install manifold plate from existing R-12 compressor on new R134a replacement compressor.

Install new pressure relief valve from retrofit kit.

Notes:

/\ Check for correct alignment of pins -E- and spring washer -D- (for suction pressure control).

/\ R-134a type replacement compressors are factory filled with R-134a compatible compressor oil. This oil does not need to be changed

Note:/\ Existing R-12 compressors equipped with an angled suction/discharge adaptor only require interchanging of the angled adaptor' to the

replacement R-134a compressor and the installation of the pressure relief valve. Manifold interchange is not necessary with thisconfiguration.

Remove bolts -D- from existing compressorTightening torque 20 Nm (15 ft Ibs).Remove manifold adaptor -A- and transfer to new R-134a replacement compressorReplace pressure relief valve -B-.O-rings -C- from R-134a replacement compressor may be used (available in kit, Part No. 4AO 298 013 AA if required).Proceed with system retrofit.

Required Parts~ Parts required,

AlC system with Zexel compressor

All models require the following parts:

/\ Zexel retrofit kit:Part No. 4AO298 107

Consisting of:

1 container (300cc) PAG refrigerant oil for Nippondenso compressors: Part No. G 052 200 A2.Pressure relief valve (with O-ring).R-134a identification labels and tag.

/\ Service valve adapterlIabel kit:Part No. 357 S20 794

/\ Restrictor*

/\ Restrictor Osrings"

/\ Compressor Osrings"

1\ Accumulator Osrings"

/\ Accumulator

Accumulator applications, systems with Zexel compressor:

Model/production90/90 Quattro, 80/S0 Quattro100/100 Quattro, 200/200 Quattro

Accumulator Part No.SAO820191 B4AO 820191 E

V8 Quattro 441 820191 A

CautionPart numbers are for reference only. Always check with your Parts Department for the latest parts information.

Retrofit ProceduresRetrofit procedure,AlC System with Zexel compressor

Discharge and capture refrigerant R-12 using Kent Moore ACRJ or equivalent.Evacuate system to remove any contaminants.Replace pressure relief valve.

A

I ""«11I1 I

Note:1\ Compressor removal may be necessary ifpressure relief valve is not accessable as installed.

Remove pressure relief valve -A- and replace with valve and O-ring supplied in retrofit kit. Tightening torque: 10 Nm (7 ft lbs).

Note:1\ Lubricate lightly with PAG refrigerant oil before installing.

If compressor is removed to replace valve, also drain and measure amount of existing refrigerant oil via oil drain plug (rotatingcompressor via the clutch will speed draining). Fill with same amount ofPAG refrigerant oil.

~: I1\ Only small amounts of refrigerant oil are present in installed, operational Zexel compressors. Unless access to pressure re ief

valves is necessary, It is not necessary to remove compressors to drain the oil.

Reinstall compressor (if removed).Remove accumulator.Clean outside of accumulator if dirty.Weigh the removed accumulator.Fill new accumulator with PAG refrigerant oil until the weight of the original accumulator is achieved.Install accumulator (use new O-rings).Replace restrictor. (use new O-rings).Identify and install correct R-134a adapters (from Kit Part No. 357 820 794) to service valve (5).

, ----.

/\ Low pressure service valve -1- (Blue), 7/l6" connection/I. High pressure service valve -2- (Red), 3/8" connection or 7/1 6"connection

- Evacuate system for a minimum of 45 minutes using Kent Moore ACR4 or equivalent.- Charge system with refrigerant R-134a, see refrigerant capacity table.- Turn compressor by hand via magnetic clutch approximately. 10 rotations.- Perform quality check and leak test.- Install new R-134a warning label,

Part No. 8AO010 132, in place of existing R-12 warning label on front crossmember or radiator cover.

Note:/\ R-134a warning label Part No. 8AO010 132 lists three R-134a fill capacities. Cross out the fill amounts not applicable to

retrofitted vehicle using a waterproof marker.

• Apply new R·134a warning label, Part No. 8AO0 I0 132 E, to visible location on compressor housing.

- Affix new R·134a warning label, Part No. 8AO010 132 G, to first page of the vehicle Maintenance Booklet.

-'~efrigerantlOil CapacityTableModel Compressor capacity90190 quattro Nlppondenso 750g +50gCoupe quattro (26.50z + 1.8oz)90/90 quanro Zaxer 6500 +SOg

(230z+ 1.80z)80180 quattro Zexel 750g .• 509

(26.502 + 1.802)

5000/5000 quattro Nlppondenso 9009 + 50g100/100 quattro (31.702 + 1.80z)2001200 quattrove quattro

100/100 quattro Zexel 900g + 50g2001200 quattro (31.7ol + 1.8oz)va quattro

Refrigerant R·134a, Capacity Table

Note:/I. R·134a warning label Part No. 8AO010 132 lists three R-134a fill capacities. When applying new R-134a label to vehicle, cross out

the fill amounts not applicable to retrofitted vehicle using a waterproof marker.

Compressor Refrfgerant system, Replacement compressor,tctal refrigerant Oil capacity refrigerant oil quantity

Nlppondenso 300 ec +/- 20 cc 80 co+/- 20 cc(10.211 oz +/- 0.711 cz) (2.7 fl OZ +/- 0.7 fl oz)

Zexel 300 +/- 20 CC 300 +/-20 cc(10.2 'I oz +1- 0.7 11oz) (10.2 110% +/- 0.7 f[ oz)

PAG Refrigerant Oil, Capacity Table

A Refrigerant oil for Nippondenso compressor Part No. 0 052 200 A2A Refrigerant oil for Zexel compressor Part No. 0 052 300 A2

Note:A Factory filled PAG oil (Part No. 0052 154 A2) in Zexel R-134a replacement compressors does not require changing.

CautionThe total system oil capacities shown are the maximum allowed for each compressor and refrigerant circuit combination.Do not exceed the total system oil capacity. Compressor damage and a decrease in cooling performance will result.PAG-oil (Poly-Alkaline-Glycol) is hygroscopic (absorbs water) After use, opened containers should be sealed immediately.PAG-oil from containers that have remained open for longer periods of time must not be used.